Hall B K
J Embryol Exp Morphol. 1980 Aug;58:251-64.
Mandibular processes from 9- to 13-day-old embryonic mice formed both bone and cartilage when grafted to the chorioallantoic membranes of most embryonic chicks. Isolated ectomesenchyme, taken from 9-day-old embryos did not form bone or cartilage, while older ectomesenchyme formed both. Recombination of the epithelial and ectomesenchymal components confirmed that the presence of the epithelium was a sufficient stimulus for the initiation of both chondro- and osteogenesis. Recombinations between components of mouse and chick mandibular processes showed that 9-day-old mouse ectomesenchyme could respond to chick epithelium but that, although older murine epithelia could initiate osteogenesis from the avian ectomesenchyme, epithelia from 9-day-old embryos could not. These results indicated that an epithelial-ectomesenchymal interaction was responsible for the initiation of both osteo- and chondrogenesis within the mandibular arch of the mouse; that the interaction began at 20 days of gestation; that the ectomesenchyme was capable of responding at 9 days, but that the epithelium did not acquire its ability to act on the ectomesenchyme until 10 days of gestation.
将9至13日龄胚胎小鼠的下颌突移植到大多数胚胎鸡的绒毛尿囊膜上时，会形成骨骼和软骨。从9日龄胚胎中分离出的外胚间充质不会形成骨骼或软骨，而较老的外胚间充质则会形成骨骼和软骨。上皮和外胚间充质成分的重组证实，上皮的存在是启动软骨生成和成骨的充分刺激因素。小鼠和鸡下颌突成分之间的重组表明，9日龄小鼠外胚间充质可以对鸡上皮做出反应，但是，尽管较老的小鼠上皮可以从禽类外胚间充质启动成骨，但9日龄胚胎的上皮却不能。这些结果表明，上皮-外胚间充质相互作用是小鼠下颌弓内成骨和软骨生成启动的原因；这种相互作用在妊娠20天时开始；外胚间充质在9天时能够做出反应，但上皮直到妊娠10天时才获得作用于外胚间充质的能力。
